Clinical and experimental data suggest that adequate control of hypertension can reduce the rate of decline in glomerular filtration rate in patients including African Americans with hypertension-related renal disease. Therefore, the National Institutes of Health is sponsoring a multi-center clinical trail, the African American Study of Kidney Disease and Hypertension, to test the hypothesis that rigorous control of blood pressure in African Americans will retard the progression of renal failure to end-stage in the clinical setting of hypertension-related kidney disease. The specific aims of the study are two-fold: (1) To determine which of three classes of antihypertensive drugs (calcium channel blockers, angiotensin converting enzyme inhibitors, or beta- blockers) is most effective in reducing blood pressure and the rate of decline in kidney function; and (2) To determine the optimum level of blood pressure control [mean arterial pressure (MAP) less than or equal to 92 mmHg versus a MAP between 102 and 107 mmHg] to achieve an effective reduction in the decline in GFR. To be included in the study patients must be African American men and women, age 18-70 years, with hypertension and some degree of reduced renal function. At least one-third of the total study population must be women. The diastolic blood pressure in the sitting position must be 95 mmHg or greater and the measured Initial GFR must be between 25 and 70 ml/min/1.73 sq.m. Major exclusion criteria include a history of accelerated or malignant hypertension within 6 months of entrance into the study, a known history of type I or type II diabetes mellitus, and proteinuria quantified by a 24 hr excretion greater than 2.5 g/24 hr or a urine protein (mg/dL) to creatinine (mg/dL) ratio exceeding 2.5. Patients will be recruited to the study during the initial 24 months. Those randomized to one of the three drug regimens and one of the two levels of blood pressure control will be followed for up to 48 months. Regular monitoring of blood pressure and renal function, the latter through measurement of the GfR, will continue throughout the period of intervention and follow-up. Several "stop" points to ensure patient safety ar built into the study protocol.